I don't understand at all what you just wrote. Why are you saying an egr valve was a mystery? I do think some good parts have been replaced unnecessarily, yet many probably were on their way out anyway and now i have backups of everything. Yes now I've learned more about that engine than I think many mechanics know about it.
Many small issues cancelled each other out to the pcm never showing any check engine or pending codes. Things kept getting worse. As new parts came in and the engine began to run better, i started getting pending codes. Now that it is running good, I have a full check engine light. Ironic. Next week hopefully the final part will arrive and hopefully fix that.

 

There are a list of conditions that must be met before the EGR Valve is supposed to operate and at what level. After that comes the extent of control.
Keep learning and I believe you will understand a lot more of what I was trying to say..

 

I have no idea of what you are trying to say. I'm explaining what has and hasn't worked, and the results of what has been done and going to be done. I'm trying to learn and be helpful at the same time so the next person who has similar issues knows what can be done. Are you saying the Valve Control Solenoid shouldn't be replaced?

 

I would not replace it unless I checked it's operation and verified it was malfunctioning.

 

I replaced the solenoid and now engine is running perfect. BUT, now cel p1443 and p1409. Why do i have more cel lights now that engine is running perfect? How can these new issues be fixed?

 

I cleaned the purge valve solenoid, reset and so far I only get pending p1406 and p1409. Hope it won't become a full cel. Any ideas?

 

I found the tube a bit loose on the DPFE sensor and now I'm just left with a p1409. I'm thinking the EGR Vacuum Solenoid I just installed may be either defective or incorrect so I ordered a different one. Driving perfect otherwise.

 

The new EGR Vacuum Solenoid was defective and after replacement everything was perfect.
After a long drive up the hill, all of a sudden I heard a loud chugging noise. The new motorcraft dpfe sensor which can only be purchased in plastic, melted through. I had no choice but to put my old metal one back in and the no power from stop and hesitation is back. I found a used metal one scheduled to arrive in a couple of weeks. Hope that one works.
Why would they only make them in plastic now?